This invention relates to a projection apparatus for optical systems such as a projection type microscope or the like, which is adapted to project an image of a sample disposed on a movable stage onto a television monitor screen and display it thereon.
Such kind of apparatus has heretofore been applied to a projection type microscope. In a known projection type microscope, an eyepiece optical system is provided at its one part with a semi-transparent mirror. The light flux transmitted through or reflected by the semi-transparent mirror is guided through a projection optical system to a screen composed of a glass plate or the like.
In such projection type microscope, the semi-transparent mirror is used so as to divide the light flux, so that the amount of light flux becomes small at both the eyepiece optical system and the projection optical system. As a result, the sample becomes so dark that it is difficult to observe it.
Particularly, if an external light incidents on the screen, the image becomes poor in contrast and it is more difficult to observe it.
In addition, the image of the sample is continuously projected onto the screen, and as a result, if the image is observed when the sample is moving, the image flows on the screen rapidly, thereby making the observation of the image difficult.